Effective color contrast. Design for people with partial vision and color problems
Three basic rules for effective color selection are mentioned here, which are perceived well by almost everyone. The following are explanations of the three properties of color in human perception — tone, brightness, and saturation — in the context of the science of vision.
How does impaired vision affect color perception?
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Partial visual impairments, age and congenital defects in color perception, lead to a decrease in the visual effectiveness of certain color combinations. Two colors that are strongly contrasted for a person with normal vision can be much worse for people with visual impairments. It is important to understand that distinctiveness depends more on the contrast between colors, and not on the characteristics of each color separately. Here are three simple rules for effectively choosing colors:
1. Increase the difference in foreground and background brightness, avoid combining colors of the same brightness, even if they differ in hue or saturation.
Do not assume that your assessment of brightness is suitable for people with impaired color perception. Make it a rule that for such people colors contrast worse than from your point of view. You will increase the visual accessibility of the design if you make the light colors lighter and the dark ones darker.
2. Combine dark colors with tones from the bottom half of this pie chart with light colors from the top half. Avoid contrasting the bright colors of the lower half and the dark colors of the upper half. The orientation of the circle in the diagram illustrates this rule.
For most people with partial loss of vision and / or congenital disorders of color perception, the brightness of the colors of the lower part tends to decrease visually.
3. Avoid building a contrast between the tones of the conjugated parts of a circle, especially if the colors do not strongly contrast in brightness.
Disadvantages of color perception associated with visual disturbances make it difficult to distinguish colors of a single tone.
Hue, brightness and saturation - three parameters of color perception - can be represented as the following three-dimensional shape:
The tone varies depending on the angle of rotation, the brightness changes from the lowest point to the top, and the saturation increases with distance from the axis of rotation.
Tone is an attribute associated with the original color names.
Tone allows you to define primary colors such as blue, green, yellow, red and purple. People with a normal perception of color note that the tone of the color form a natural sequence, based on the similarity of one tone with another. The main disadvantages of perception of color lead to the fact that the ability to distinguish colors by tone is weakened.
Brightness is related to how much light will be reflected from the painted surface relative to the light reflected from other surfaces.
Brightness, like tone, is a property of perception that cannot be calculated only from physical measurements. Brightness is the most important parameter in increasing the effectiveness of contrast.
Disadvantages of color perception reduce the ability to distinguish colors in brightness.
A person with color perception can see the left half of the diagram just as a person with normal perception sees the right half.
With the lack of perception of color, the ability to distinguish colors by tone, brightness and saturation is weakened. Designers can help people compensate for shortcomings by increasing the differences in colors in all three parameters.
How does impaired vision affect color perception?
')
Partial visual impairments, age and congenital defects in color perception, lead to a decrease in the visual effectiveness of certain color combinations. Two colors that are strongly contrasted for a person with normal vision can be much worse for people with visual impairments. It is important to understand that distinctiveness depends more on the contrast between colors, and not on the characteristics of each color separately. Here are three simple rules for effectively choosing colors:
1. Increase the difference in foreground and background brightness, avoid combining colors of the same brightness, even if they differ in hue or saturation.
Do not assume that your assessment of brightness is suitable for people with impaired color perception. Make it a rule that for such people colors contrast worse than from your point of view. You will increase the visual accessibility of the design if you make the light colors lighter and the dark ones darker.
2. Combine dark colors with tones from the bottom half of this pie chart with light colors from the top half. Avoid contrasting the bright colors of the lower half and the dark colors of the upper half. The orientation of the circle in the diagram illustrates this rule.
For most people with partial loss of vision and / or congenital disorders of color perception, the brightness of the colors of the lower part tends to decrease visually.
3. Avoid building a contrast between the tones of the conjugated parts of a circle, especially if the colors do not strongly contrast in brightness.
Disadvantages of color perception associated with visual disturbances make it difficult to distinguish colors of a single tone.
Hue, brightness and saturation - three parameters of color perception - can be represented as the following three-dimensional shape:
The tone varies depending on the angle of rotation, the brightness changes from the lowest point to the top, and the saturation increases with distance from the axis of rotation.
Tone is an attribute associated with the original color names.
Tone allows you to define primary colors such as blue, green, yellow, red and purple. People with a normal perception of color note that the tone of the color form a natural sequence, based on the similarity of one tone with another. The main disadvantages of perception of color lead to the fact that the ability to distinguish colors by tone is weakened.
Brightness is related to how much light will be reflected from the painted surface relative to the light reflected from other surfaces.
Brightness, like tone, is a property of perception that cannot be calculated only from physical measurements. Brightness is the most important parameter in increasing the effectiveness of contrast.
Disadvantages of color perception reduce the ability to distinguish colors in brightness.
A person with color perception can see the left half of the diagram just as a person with normal perception sees the right half.
With the lack of perception of color, the ability to distinguish colors by tone, brightness and saturation is weakened. Designers can help people compensate for shortcomings by increasing the differences in colors in all three parameters.
Source: https://habr.com/ru/post/31384/
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